Let a given periodic signal satisfys(n1, n2) = s(n1 + 5, n2 + 3) = s(n1 – 1, n2 – 3) for all n1, n2. (a)What is the corresponding periodicity matrix N? (b)Is 푠푠also periodic with vectors풏풏1=�40� and 풏풏2=�3−3� ?